If cancer is identified in the early stages, treatment can be highly effective. However, in the latter stages of the disease, as the cancer spreads to other organs, treatment becomes more difficult. Detecting metastatic cancer in the early stages allows physicians to commence treatment quickly before secondary tumors start to grow.
A number of devices have been developed that are capable of detecting circulating cancer cells (CTC). Those devices use a range of techniques to detect CTCs such as microfluidic chips, immunomagnetics, nano-Velcro arrays, and laser scanning cytometry. However, a research team at Worcester Polytechnic Institute in Massachusetts (WPI) has developed a new method of detection that uses a chip containing carbon nanotubes. The technique and technology could be used in a simple blood test that can be quickly and easily performed to determine whether CTCs are present in the blood.
Currently, microfluidic techniques only allow CTCs to be captured. Off-chip post-processing is required to identify the CDCs. Until now, microfluidics could not be incorporated into a quick and easy blood test for CTCs. However, the WPI researchers developed a new chip that includes an array of carbon nanotubes at the bottom of 3-millimeter wells in the chip.
Specific antibodies are attached to the nanotubes, which each bind to a single type of cancer cell. When blood is placed in the well, cancer cells, being heavier, fall to the bottom where they bind to the antibodies. When a cancer cell binds to an antibody, electrodes in the chip detect the electrical change confirming the presence of CTCs.
The technique can be used to detect many different types of cancer cells. The researchers say it is possible to isolate several different types of cancer cells in a single test from a single blood sample. Using a chip with 170 wells the researchers were able to isolate up to 1,000 cells per device using just 0.85 milliliters of blood.
In addition to capturing and analyzing CDCs on-chip, the researchers say the technique also allows exosomes to be captured, which is not possible using other types of liquid biopsy devices. WPI associate professor of mechanical engineering, Balaji Panchapakesan, says “Our chip is currently the only device that can potentially capture circulating tumor cells and exosomes directly on the chip, which should increase its ability to detect metastasis.”
The researchers believe that their device is virtually ready for commercialization, although first they need to collect more data on patients with cancer at different stages.
The research has recently been published in the journal Nanotechnology.